bad disk message with ritek dvd-r

after trying almost every dvdr known to man, ive found ritek to be best, however every second disk i burn, i get a message on my stand alone saying bad disk.the disk works ok on my pc. im using shrink and nero burning at 4speed. so out of a pack of 10 disks 5 wont work, im totally baffled please help

Take your fine self and 3 or 4 of your “won’t play in my standalone player” off to the local “Mall” or “Electronics Boutique” where there are many DVD players on display and try them there -

My thoughts are that you’ll be then headed home to address your standalone player. “Mr. Player, continue in your wicked ways and you’ll be replaced by an “El Cheapo” player which will read dirty coffee cup saucers”